Final answer:
Condensed chromatin leads to the silencing of genes due to compacted nucleosomes. Acetylation of chromatin results in a less compact structure, activating gene expression. Deacetylation, conversely, silences genetic transcription by promoting chromatin condensation.
Step-by-step explanation:
Matching the chromatin structure and its effect on gene expression results in the following associations:
- Condensed chromatin - C. compacted nucleosomes. This refers to the tightly coiled state of chromatin that generally silences genetic transcription by making the DNA inaccessible to transcription machinery.
- Acetylation of chromatin - B. less compact structure. The addition of acetyl groups to histone proteins decreases the positive charge, leading to a more open conformation that activates genes and allows transcription factors to bind the DNA, thus activating gene expression.
- Deacetylation - A. activate genes. This would be an incorrect match; the correct match for deacetylation is D. silences genetic transcription. Deacetylation of histones leads to a more condensed nucleosome structure, thereby silencing gene expression.
Deacetylation in fact leads to a more condensed chromatin structure, which would silence genes rather than activating them. This process is part of the dynamic regulation of gene expression through epigenetic changes that can be reversed, allowing for flexibility in gene transcription regulation.